Why you should care

Sixteen-odd Republican candidates couldn’t do it this year. Nor could a “Never Trump” movement, including some of the GOP’s leading figures. Nor could Hillary Clinton. So if there was indeed no one in 2016 who could beat Donald Trump, who might have the best chance of pulling it off in 2020 (assuming a Trump presidency lasts that long)? A major Democratic figure who’s known for her consumer advocacy? A turncoat in Trump’s own party (Et tu, Ted?)? Or perhaps an insurgent outsider who, just like Trump, comes from another world than politics? It’s early, but OZY takes a look at some possibilities.

Democratic Contenders: Senate Heavyweights and Rising Stars

The Democrats will likely have a broad but not particularly strong field in 2020, and one without a clear front-runner like Clinton, so we can probably expect something similar to the 15-plus candidates competing in the GOP primary this year, says Steffen Schmidt, a political science professor at Iowa State University. And headlining that pool of candidates will be some Democratic senators who have been patiently awaiting their turn — and the passage of the Clinton train — to take a shot at the presidency. At the top of everyone’s list will be Massachusetts Senator Elizabeth Warren, a prodigious fundraiser and party favorite. And, if this year’s election is any indication, Warren would then likely be the party’s most outspoken opponent of a President Trump in Congress, which would put her on course for an electoral confrontation with Trump.

.@realDonaldTrump makes death threats because he’s a pathetic coward who can’t handle the fact that he’s losing to a girl.

Two of the parties’ rising Senate stars will also top the list. A New York senator like Clinton was, Kirsten Gillibrand has close connections to Clinton’s political network and a loyal following of female supporters and donors within the party. The Democrats’ best bet in 2020, though, says Northeastern University politics professor Daniel Urman, is to replicate the winning coalition of young, minority and progressive voters that President Obama put together in 2008 and 2012 (but that Clinton failed to turn out). The most likely person to pull that off? Cory Booker. Not only is the New Jersey senator a smart and charismatic politician who would energize young and minority voters, the major knock against him over the years — that he is an overly ambitious publicity-seeker — doesn’t sound so bad in a post-Trump electoral environment.

Sen. Amy Klobuchar at the Democratic National Convention in Philadelphia, July 26, 2016.

Also watch out for another senator, Schmidt says: Amy Klobuchar of Minnesota. Klobuchar is one of the most popular figures in the party and was on a lot of VP short lists this year, but she is also relatively centrist, and the mood within the party by the end of four years of Trump may well demand embracing a more progressive figure that pulls in more Bernie Sanders’ supporters to oppose the GOP. Advantage: Warren.

Finally, one long shot worth mentioning is Tim Kaine. A possibility — but one that will not be as fresh in 2020 and could be damaged by being on a losing ticket this year. HUD Secretary Julián Castro’s name surfaced a lot in Veepstakes speculation this year, but the rising Latino star can only be ascendant for so long and will need to add a national office, or a governorship, to bolster his résumé before 2020.

Republican Turncoats and Party Outsiders

Incumbent presidents rarely face primary challengers in their bid for re-election. And when they do — as with Ronald Reagan’s challenge of Gerald Ford in 1976, Ted Kennedy’s taking on Jimmy Carter in 1980 and Pat Buchanan’s bid to unseat George H.W. Bush in 1992 — it’s usually because that incumbent is viewed as unsuccessful or unpopular, particularly within a party’s base.

There’s a good chance that Trump will ride a turbulent presidency, but would it be enough to spark a primary challenge four years from now? Trump would need to be “imploding” to face any real opposition, Schmidt says. Which is not beyond the realm of possibility. But it does seem unlikely that major party figures like House Speaker Paul Ryan or young party stars like Wisconsin Governor Scott Walker or Arkansas Senator Tom Cotton would challenge the candidate they endorsed, at one point or another, this year.

A Trump slayer could emerge who didn’t run in 2016 …

Indeed, the candidates most likely to challenge Trump during the next presidential election cycle may well be the same ones he burned this year: Ted Cruz,Marco Rubio and John Kasich. Given Rubio’s distaste for the Senate, you have to assume that he wouldn’t have changed his mind and sought re-election unless he didn’t still have his eye on the presidency. And Cruz may have belatedly endorsed Trump, but who among us doubts that his “conscience” could result in him changing his mind (yet) again should the political winds shift?

Of course, a Trump slayer could emerge who didn’t run in 2016. South Carolina Governor Nikki Haley and Nebraska Senator Ben Sasse were both high-profile opponents of Trump this year. Would either rising star risk their future in the party by challenging a sitting president — a task usually reserved for outsiders (Buchanan) or leaders with an established following (Kennedy, Reagan)? A better bet to challenge Trump would perhaps be a nonparty outsider like billionaire Mark Cuban. Still, a “Trump-lite” outsider candidate would likely fare much better in the wake of a Trump loss than in trying to dethrone the real deal himself.

In fact, as Urman reminds us, given the media and administrative advantages of the modern presidency, it is extremely difficult to unseat any incumbent — even a potentially volatile one like Trump. So signing up for one term of the Donald may mean a good chance at getting two, regardless of the caliber of the opposition.